The invention relates to metal lysine complexes and, more particularly, to metal lysine complexes, a method of producing the same, and the nutritional supplementation of living organisms with the metal lysine complexes.
It has long been recognized that certain "trace" metals are essential to the health of all living organisms. Such trace metals serve well established functions in enzyme reactions, as components of electrolytes, as binding sites in the transport of oxygen, and as structural components of nonenzymatic macromolecules.
Dietary supplementation is, of course, of greater importance when the organism is being fed a limited diet or ration. For example, agricultural animals are frequently fed a ration comprised of a single grain component, sometimes supplemented by the addition of an amino acid or protein concentrate. Not all of the essential trace metals will be present in biologically required quantities in any single grain, and likely not in any combination ration of two or three grains. With the discovery of the importance of trace metals, dietary supplementation was attempted by the addition of the ionic salts of the trace metals, such as iron sulphate, zinc chloride, copper sulphate, and so on. The bioavailability of the trace metals from the salts is variable because of the poor assimilation of the ionic metal salts in the gastrointestinal track. Dietary supplementation has also been attempted by the use of metal chelates. The binding strength of such compounds to the trace metal component, however, may limit the availability of the metal for assimilation by the organism.
The metal lysine complexes of this invention are formed with iron, copper, zinc, manganese, and cobalt, all of which play important roles in metabolic processes. Iron is the most abundant trace element in the bodies of both humans and animals. The principal function of iron is as the oxygen transport binding site in hemoglobin. Anemia, accordingly, is an early effect of iron deficiency.
Copper plays an important role in several enzymatic functions, particularly the oxidation and transport of iron. Copper has been shown to play a role in the healing process and connective tissue repair, the inhibition of carcinogenesis in laboratory animals, and in the immune function.
Deficiencies of zinc can result in growth retardation, skin lesions, diarrhea, and impaired wound healing. Zinc is necessary for the activity of more than 90 human enzymes associated with carbohydrate and energy metabolism, protein degradation, nucleic acid synthesis, carbon dioxide transport, and many other reactions.
Manganese is associated with a large number of enzymes, such as acetyl-CoA carboxylases and isocitrate dehydrogenase in the Krebs cycle and mitochondria. Manganese is important for the growth and maintenance of connective tissue, cartilage, and bone. While manganese is present in the mineral component of bone, bone manganese is not an available source for use by the soft tissues.
Cobalt is an intrinsic part of vitamin B.sub.12 and, as such, is required in the synthesis of methionine, an essential amino acid, and in the utilization of odd-numbered carbon fatty acids. While the biological role of cobalt is, as yet, largely unknown, it is known to have an important stimulating effect on the formation of red blood cells.
Lysine is an essential amino acid in the diet of mammals. That is, lysine cannot be synthesized by mammals at a rate adequate to meet metabolic requirements and so must be supplied in the diet. Corn (Zea mays L.) is notoriously low in lysine and, if used in a single grain ration, requires lysine supplementation to maintain animal health and for economical animal growth. The present invention, by forming metal lysine complexes, supplements both trace metals and the essential amino acid lysine by the addition of a single dietary supplement. It is believed that the metal component of the metal lysine complex is more easily transported through the intestinal wall with the lysine component than when in the form of an ionic salt. Lesser amounts of the metals, accordingly, may be added to the diet to effect adequate supplementation.
An important object of the invention is to provide an efficient and low cost method for preparing metal lysine complexes which provide readily assimilable forms of the trace metals iron, copper, zinc, manganese, and cobalt and the essential amino acid lysine for the dietary supplementation of these materials in plants, animals, and man.